Friday, May 08, 2009

A (H1N1), FLU: VACCINES and ANTIVIRALS

Abstract from New Scientist.

The fear to a second wave (more lethal), of the virus A (H1N1), promotes critics and varied strategies: I) The OMS recommends antiviral employment: Tamiflu (oseltamivir) and Relenza (zanamivir), in early stages of the illness of the current influenza, as long as they would shorten the time of illness and would diminish the severity of the same one. Under such a premise some countries have accumulated millions of antiviral doses allowing the prosperity of some companies. The problem is the growing resistance to antivirals, with what the doubts about its effectiveness grow. A recent study revealed that constant washing of hands save more lives than antivirals. Recent studies, point out a growing resistance to Tamiflu, fact that prompted the last year to combine Relenza with COX-2 non-steroid antiinflamatory inhibitors, had bill that during the severe cases of influenza a cytoquine storm is unchained. II) Another strategy is to achieve that B cells, produce monoclonal antibodies against the virus in less than 1 month. Others tried to remove B cells from survivors or from people vaccinated with particular stumps. Also to extract producing antibodies genes, inserting them in existent B cells existent increasing their protein load. Also are important plasmatic antibodies secretor cells (ASCs), of short life (80% is isolated 7 days after the vaccination), containing monoclonal antibodies that bind specifically to the virus.

III) Inside this view, it is clear that the best are the vaccines. Dr Walter Fierstries to create a vaccine capable of eliminating the seasonal influenza, offering also protection against pandemics. For it Fiers focalized his attention in a proteic segment (M2e), important for not unchaining immune answer (anti-M2) in convalescent. M2e, is plentiful inside lung cells. Fiers sustains that if in an early stadium are killed the cells that contain them, it would be possible stop the infection. The universal vaccine of Fiers is focalized in parts of the virus that not mute, being therefore effective even when the virus evolves. A vaccine not invalidated by the viral shift and drift. If there was not drift, accumulation of punctual mutations would not exist. If shift didn't exist, there would not be exchange of genes of animal stumps to human, having vaccines based exclusively on serologic data. Others has in mind to generate vaccines starting from parts of the surface of genes (DNA), of influenza virus, the same ones that injected in the skin, are taken by immune cells being later transformed into proteins. Adolfo García-Sastre, has prepared a vaccine for pigs based on altered genetically alive virus so they cannot be replied actively, neither to generate antibodies different to those of an infection. Finally, consensus exists in replacing the obsolete method of preparing vaccines using immense quantities of fertilized chicken eggs, for others in that alone cells of mammals are used, to reproduce the virus.